Zheng Helin, Zhang Xuemei, Tian Lu, Liu Bo, He Xiaoya, Wang Longlun, Ding Shuang, Guo Yi, Cai Jinhua
Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Department of Radiology, National Clinical Research Center for Child Health and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.
Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Department of Medical Affairs, National Clinical Research Center for Child Health and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.
Front Neurosci. 2023 Jan 6;16:1028762. doi: 10.3389/fnins.2022.1028762. eCollection 2022.
Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is one of the most common inherited mitochondrial disorders. Due to the high clinical and genetic heterogeneity of MELAS, it is still a major challenge for clinicians to accurately diagnose the disease at an early stage. Herein, we evaluated the neuroimaging findings of MELAS with an mutation in and analyzed the possible underlying pathogenesis of stroke-like episodes.
Fifty-nine imaging studies in 24 patients who had a confirmed genetic diagnosis of ( ) associated with MELAS were reviewed in our case series. The anatomic location, morphological features, signal/intensity characteristics and temporal evolution of lesions were analyzed on magnetic resonance imaging (MRI), and computed tomography (CT) images. The supplying vessels and metabolite content of the lesions were also evaluated by using MR angiography (MRA)/CT angiography (CTA), and MR spectroscopy (MRS), respectively.
The lesions were most commonly located in the posterior brain, with 37 (37/59, 63%) in the occipital lobe, 32 (32/59, 54%) in the parietal lobe, and 30 (30/59, 51%) in the temporal lobe. The signal characteristics of the lesions varied and evolved over time. Bilateral basal ganglia calcifications were found in 6 of 9 (67%) patients who underwent CT. Cerebral and cerebellar atrophy were found in 38/59 (64%) and 40/59 (68%) patients, respectively. Lesion polymorphism was found in 37/59 (63%) studies. MRS showed elevated lactate doublet peaks in 9/10 (90%) cases. MRA or CTA revealed that the lesion-related arteries were slightly dilated compared with those of the contralateral side in 4 of 6 (67%) cases.
The imaging features of MELAS vary depending on the disease stage. Polymorphic lesions in a single imaging examination should be considered a diagnostic clue for MELAS. Stroke-like episodes may be involved in a complex pathogenetic process, including mitochondrial angiopathy, mitochondrial cytopathy, and neuronal excitotoxicity.
线粒体脑肌病伴乳酸酸中毒和卒中样发作（MELAS）是最常见的遗传性线粒体疾病之一。由于MELAS具有高度的临床和遗传异质性，临床医生在疾病早期准确诊断该病仍是一项重大挑战。在此，我们评估了携带 突变的MELAS患者的神经影像学表现，并分析了卒中样发作可能的潜在发病机制。
在我们的病例系列中，回顾了24例经基因确诊为与MELAS相关的 （ ）患者的59项影像学研究。在磁共振成像（MRI）和计算机断层扫描（CT）图像上分析病变的解剖位置、形态特征、信号/强度特征及时间演变。病变的供血血管和代谢物含量分别通过磁共振血管造影（MRA）/CT血管造影（CTA）和磁共振波谱（MRS）进行评估。
病变最常见于后脑，枕叶有37处（37/59，63%），顶叶有32处（32/59，54%），颞叶有30处（30/59，51%）。病变的信号特征随时间变化。在接受CT检查的9例患者中，有6例（67%）发现双侧基底节钙化。分别在38/59（64%）和40/59（68%）的患者中发现大脑和小脑萎缩。在37/59（63%）的研究中发现病变多态性。MRS显示9/10（90%）的病例中乳酸双峰升高。MRA或CTA显示，6例中有4例（67%）病变相关动脉与对侧相比略有扩张。
MELAS的影像学特征因疾病阶段而异。单次影像学检查中的多态性病变应被视为MELAS的诊断线索。卒中样发作可能涉及复杂的发病机制，包括线粒体血管病线粒体细胞病和神经元兴奋毒性。
